Suction nozzle and electric vacuum cleaner including the same

ABSTRACT

A suction nozzle of an electric vacuum cleaner including an electric blower, includes a suction inlet; an outlet; a suction passage extending along a center line joining a middle of the suction inlet in the longitudinal direction and a middle of the outlet in the longitudinal direction to connect the suction inlet and the outlet; and partition walls arranged in the suction passage to extend from the suction inlet side to the outlet side. The suction passage includes a main passage and division passages arranged on both outer sides of the main passage. The main passage and the division passages are divided in the longitudinal direction of the suction inlet by the partition walls. A width of the main passage at the suction inlet measured in the longitudinal direction is arranged to be greater than a width of the main passage at the outlet measured in the longitudinal direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Japan application serialno. 2016-094466, filed on May 10, 2016. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The disclosure relates to a suction nozzle for sucking air, and anelectric vacuum cleaner including the same.

2. Description of the Related Art

A known electric vacuum cleaner is disclosed in JP-A 2015-70960. Thiselectric vacuum cleaner includes a case including an air inlet and adischarge outlet for air, and an air passage that connects the air inletand the discharge outlet is defined in the case. In the air passage, anelectric blower that produces an air flow is arranged, and a dustcollection portion that collects waste flowing in the air passage, suchas, for example, dust, is arranged on the upstream side of the electricblower. Left and right wheels are attached to both side surfaces of thecase. The case is thus able to travel on a floor in a room.

A hose is connected to the air inlet of the case, and a connection pipeis connected to an upstream end of the hose. A handle and an operationswitch are arranged in the connection pipe. The operation switch isoperated to, for example, turn on or off the electric vacuum cleaner,and change the rotation rate of the electric blower. An extension pipeis attached to an upstream end of the connection pipe. A suction head isattached to an upstream end of the extension pipe such that the suctionhead is detachable from the extension pipe. The suction head includes ahousing extending in a direction substantially perpendicular to adirection in which the extension pipe extends.

In a bottom portion of the housing of the suction head, a suctionopening portion extending in a longitudinal direction of the housing isopen and is arranged opposite to the floor. A substantially circularoutlet which is in communication with the extension pipe is open in anupper portion of a longitudinal middle portion of the housing of thesuction head. The suction opening portion is arranged to extend betweenboth longitudinal end portions of the housing, while a dimension of theoutlet measured in the longitudinal direction of the housing is arrangedto be smaller than that of the suction opening portion. A suctionchamber that connects the suction opening portion and the outlet isdefined in the housing.

If the operation switch of the electric vacuum cleaner having theabove-described structure is operated to drive the electric blower, airincluding waste, such as, for example, dust, is sucked into the suctionchamber through the suction opening portion of the suction head. Afterbeing sucked into the suction head, the air flows in the suctionchamber, and flows into the extension pipe through the outlet. Afterflowing into the extension pipe, the air flows into the case through thehose, and the waste in the air is collected in the dust collectionportion in the case. The floor is thus cleaned.

However, in the suction head (i.e., a suction nozzle) of theabove-described known electric vacuum cleaner, the outlet is open in thelongitudinal middle portion of the housing. Therefore, portions of airflows sucked in through both end portions of the suction opening portion(i.e., a suction inlet) with respect to the longitudinal directionabruptly bend toward a longitudinal middle immediately after enteringinto the suction chamber (i.e., a suction passage), and join an air flowsucked in through a longitudinal middle portion of the suction openingportion. This may cause a turbulence in the suction chamber, resultingin reduced suction efficiency of the suction head.

SUMMARY OF THE DISCLOSURE

A suction nozzle according to a preferred embodiment of the disclosureis a suction nozzle to be provided in an electric vacuum cleanerincluding an electric blower, the suction nozzle including a suctioninlet arranged to extend in a longitudinal direction that ispredetermined, and arranged opposite to a surface to be cleaned; anoutlet to be connected to the electric blower; a suction passagearranged to extend along a center line joining a middle of the suctioninlet in the longitudinal direction and a middle of the outlet in thelongitudinal direction to connect the suction inlet and the outlet; anda plurality of partition walls each of which is arranged in the suctionpassage to extend from a side on which the suction inlet is defined to aside on which the outlet is defined. The suction passage includes a mainpassage having the center line of the suction passage passingtherethrough; and a plurality of division passages arranged on bothouter sides of the main passage with respect to the longitudinaldirection with one of the partition walls being arranged between themain passage and an adjacent one of the division passages on either sideof the main passage. The main passage and the division passages aredivided from one another in the longitudinal direction of the suctioninlet by the partition walls. A width of the main passage at the suctioninlet measured in the longitudinal direction is arranged to be greaterthan a width of the main passage at the outlet measured in thelongitudinal direction.

An electric vacuum cleaner according to a preferred embodiment of thedisclosure includes the above suction nozzle, a dust collection portionarranged downstream of the suction nozzle, and an electric blowerarranged downstream of the dust collection portion.

The suction nozzle according to the above preferred embodiment of thedisclosure is able to achieve improved suction efficiency. In addition,according to a preferred embodiment of the disclosure, an electricvacuum cleaner including the above suction nozzle is provided.

The above and other elements, features, steps, characteristics andadvantages of the disclosure will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electric vacuum cleaner according toa first preferred embodiment of the disclosure.

FIG. 2 is a bottom view of the electric vacuum cleaner according to thefirst preferred embodiment of the disclosure.

FIG. 3 is a side sectional view of the electric vacuum cleaner accordingto the first preferred embodiment of the disclosure.

FIG. 4 is a perspective view of a portion of an air passage on thesuction side including a suction nozzle of the electric vacuum cleaneraccording to the first preferred embodiment of the disclosure.

FIG. 5 is a sectional front view of the suction nozzle of the electricvacuum cleaner according to the first preferred embodiment of thedisclosure.

FIG. 6 is a perspective view illustrating a result of a simulation offlows of air in the portion of the air passage on the suction side ofthe electric vacuum cleaner according to the first preferred embodimentof the disclosure.

FIG. 7 is a side view illustrating the result of the simulation of theflows of air in the portion of the air passage on the suction side ofthe electric vacuum cleaner according to the first preferred embodimentof the disclosure.

FIG. 8 is a side view illustrating a result of a simulation of an airvelocity distribution in the portion of the air passage on the suctionside of the electric vacuum cleaner according to the first preferredembodiment of the disclosure.

FIG. 9 is a side view illustrating a result of a simulation of an airpressure distribution in the portion of the air passage on the suctionside of the electric vacuum cleaner according to the first preferredembodiment of the disclosure.

FIG. 10 is a perspective view of a portion of an air passage on thesuction side including a suction nozzle of an electric vacuum cleaneraccording to a second preferred embodiment of the disclosure.

FIG. 11 is a sectional front view of the suction nozzle of the electricvacuum cleaner according to the second preferred embodiment of thedisclosure.

FIG. 12 is a perspective view of a portion of an air passage on thesuction side including a suction nozzle of an electric vacuum cleaneraccording to a third preferred embodiment of the disclosure.

FIG. 13 is a sectional front view of the suction nozzle of the electricvacuum cleaner according to the third preferred embodiment of thedisclosure.

FIG. 14 is a perspective view of an electric vacuum cleaner according toa fourth preferred embodiment of the disclosure.

FIG. 15 is a sectional front view of a suction nozzle of the electricvacuum cleaner according to the fourth preferred embodiment of thedisclosure.

FIG. 16 is a side sectional view of the suction nozzle of the electricvacuum cleaner according to the fourth preferred embodiment of thedisclosure.

FIG. 17 is a perspective view of an electric vacuum cleaner according toa fifth preferred embodiment of the disclosure.

FIG. 18 is a perspective view of an electric vacuum cleaner according toa sixth preferred embodiment of the disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the disclosure will be describedin detail with reference to the accompanying drawings. It is assumedherein that a direction toward a floor F (i.e., a surface to be cleaned)illustrated in FIG. 3 is a downward direction, while a direction awayfrom the floor F is an upward direction. It is also assumed herein that,with respect to a front-rear direction, a direction leading from anelectric blower 7 to a suction inlet 4 is a forward direction, while adirection leading from the suction inlet 4 to the electric blower 7 is arearward direction. It is also assumed herein that a directionperpendicular to the front-rear direction and parallel to the floor F isa right-left direction (i.e., a longitudinal direction). It is alsoassumed herein that a surface parallel to the front-rear direction andperpendicular to the right-left direction is referred to as a “sidesurface”. It is also assumed herein that an upstream side and adownstream side are defined with respect to a direction in which airsucked in through the suction inlet 4 when the electric blower 7 is inoperation flows. It is also assumed herein that the wording “the suctioninlet 4 arranged opposite to the floor F (i.e., the surface to becleaned)” and the like can refer to a situation in which the suctioninlet 4 and the floor F face each other with another member (e.g., arotary brush, etc.) arranged therebetween, in addition to a situation inwhich the suction inlet 4 and the floor F face each other directly withno other member arranged between the suction inlet 4 and the floor F.

An electric vacuum cleaner 1 according to a first preferred embodimentof the disclosure will be described below. FIGS. 1, 2, and 3 are aperspective view, a bottom view, and a side sectional view,respectively, of the electric vacuum cleaner 1 according to the firstpreferred embodiment. The electric vacuum cleaner 1 is a so-calledrobot-type electric vacuum cleaner, and includes a case 2 which issubstantially circular in a horizontal section (i.e., a section parallelto the floor F).

A display portion 15 and an operation portion 16 are arranged in anupper surface of the case 2. The operation portion 16 includes aplurality of buttons (not shown). By operating the operation portion 16,a user can, for example, issue an instruction to turn on or off theelectric vacuum cleaner 1, issue an instruction to change the rotationrate of the electric blower 7, which will be described below, or enter acondition, such as, for example, a time at which the electric vacuumcleaner 1 is to start cleaning. The display portion 15 includes, forexample, a liquid crystal display panel or the like, and displays, forexample, the condition entered with the operation portion 16.

In addition, a position sensor (not shown) is arranged in the uppersurface of the case 2. The position sensor is used to detect theposition of the electric vacuum cleaner 1 in a room, for example.

The suction inlet 4, which is arranged to extend in the right-leftdirection (i.e., a longitudinal direction A), is defined in a bottomsurface (i.e., a lower surface) of the case 2, and a discharge outlet 5,which is arranged to extend in the right-left direction, is defined in arear portion of the case 2. The suction inlet 4 is arranged opposite tothe floor F (i.e., the surface to be cleaned) inside the room, and thedischarge outlet 5 is arranged to face obliquely rearward and upwardfrom the case 2. A rotary brush (not shown) is arranged in the vicinityof the suction inlet 4 in a bottom portion of the case 2. Note that therotary brush may alternatively be arranged in the suction inlet 4.

An air passage 6, which connects the suction inlet 4 and the dischargeoutlet 5, is arranged inside of the case 2. The electric blower 7, whichis arranged to produce an air flow, is arranged in the air passage 6.Once the electric blower 7 is driven, air in the room flows into the airpassage 6 through the suction inlet 4 as indicated by arrows S, and issent out into the room through the discharge outlet 5. A centrifugal fanis preferably used as the electric blower 7, but other types of electricblowers, such as, for example, an axial flow fan, may alternatively beused.

In the air passage 6, a dust collection portion 8 and a filter 9 arearranged in the order named from the upstream side to the downstreamside with respect to the direction in which the air flows between thesuction inlet 4 and the electric blower 7. Dust included in the airflowing in the air passage 6 is blocked by the filter 9, and iscollected in the dust collection portion 8, which is defined in theshape of a container. Each of the dust collection portion 8 and thefilter 9 is detachably fitted in the case 2. On the downstream side ofthe filter 9, the air passage 6 is arranged to decrease in a channelwidth (i.e., width in the longitudinal direction A) toward an air inlet(not shown) of the electric blower 7.

A suction nozzle 20 in the shape of a nozzle is detachably fitted in thecase 2 on the upstream side of the dust collection portion 8 in the airpassage 6. The suction nozzle 20 includes the suction inlet 4 and anoutlet 22 at an upstream end and a downstream end, respectively, and asuction passage 21 which connects the suction inlet 4 and the outlet 22is defined in the suction nozzle 20. The suction inlet 4 is arranged toextend in the predetermined longitudinal direction A, and is arrangedopposite to the floor F (i.e., the surface to be cleaned). The outlet 22is connected to the electric blower 7. The width of the outlet 22measured in the longitudinal direction A is arranged to be substantiallyequal to the width of the suction inlet 4 measured in the longitudinaldirection A.

The suction passage 21 is arranged to extend upward from the suctioninlet 4 and curve rearward, and is connected to an upper portion of thedust collection portion 8 through the outlet 22. The upper side of aportion of the dust collection portion 8 is covered with the suctionnozzle 20. That is, the suction passage 21 is arranged to extend upwardfrom the suction inlet 4, and is connected to the upper portion of thedust collection portion 8, and the upper side of a portion of the dustcollection portion 8 is covered with the suction nozzle 20. The detailsof the suction nozzle 20 will be described below.

Left and right drive wheels 19 a are arranged at left and right endportions of the bottom surface of the case 2. A trailer wheel 19 b,which is defined by a caster, is arranged at a front end portion of thebottom surface of the case 2. Each drive wheel 19 a is connected to adrive motor (not shown). The case 2 is thus able to travel on the floorF.

In addition, the electric vacuum cleaner 1 includes a control portion(not shown) which controls various portions of the electric vacuumcleaner 1. The electric blower 7, the display portion 15, the operationportion 16, the drive motor, the position sensor, a storage portion, andso on are connected to the control portion. The storage portion isarranged to store a control program for the electric vacuum cleaner 1and, in addition, the condition entered with the operation portion 16and so on.

A power supply portion 11 including a secondary battery and so on isarranged in a front portion of the case 2. The power supply portion 11is arranged to supply power to the electric blower 7, the controlportion, the drive motor, and so on, and includes a case-side contactpoint (not shown) exposed in the bottom surface of the case 2. Thecase-side contact point is arranged to make contact with a chargerstand-side contact point of a charger stand (not shown) connected to acommercial power supply (not shown). The secondary battery of the powersupply portion 11 is thus charged through the charger stand. Before acleaning operation is started, the electric vacuum cleaner 1 is placedon the charger stand.

FIG. 4 is a perspective view of a portion of the air passage 6 on thesuction side including the suction nozzle 20, and FIG. 5 is a sectionalfront view of the suction nozzle 20. The suction nozzle 20 includes thesuction inlet 4, the outlet 22, the suction passage 21, and a pluralityof partition walls 25. The suction passage 21 is arranged to extendalong a center line CT, which joins a middle of the suction inlet 4 inthe longitudinal direction A and a middle of the outlet 22 in thelongitudinal direction A, to connect the suction inlet 4 and the outlet22. Upper and lower surfaces of the suction passage 21 are defined by anupper wall 28 a and a lower wall 28 b, respectively, and left and rightsurfaces of the suction passage 21 are defined by a side wall 28 c and aside wall 28 d, respectively. Each of the upper wall 28 a and the lowerwall 28 b is arranged to slant in such a manner as to increase in heightas the upper wall 28 a or the lower wall 28 b extends rearward, and thesuction passage 21 is arranged to slant and guide an air flow to theoutlet 22.

In the suction passage 21, the plurality of (two in the presentpreferred embodiment) partition walls 25 are arranged side by side inthe longitudinal direction A. Each of the partition walls 25 is arrangedin the suction passage 21, and is arranged to extend from a side onwhich the suction inlet 4 is defined to a side on which the outlet 22 isdefined. The partition walls 25 are arranged to extend from the suctioninlet 4 to the outlet 22 to divide the suction passage 21 into a mainpassage 21 a and a plurality of (two in the present preferredembodiment) division passages 21 b and 21 c, which are divided from oneanother in the longitudinal direction A. The main passage 21 a has thecenter line CT of the suction passage 21 passing therethrough. Thedivision passages 21 b and 21 c are arranged on both outer sides of themain passage 21 a with respect to the longitudinal direction A with oneof the partition walls 25 being arranged between the main passage 21 aand an adjacent one of the division passages 21 b and 21 c on eitherside of the main passage 21 a. The main passage 21 a and the divisionpassages 21 b and 21 c are divided from one another in the longitudinaldirection A of the suction inlet 4 by the partition walls 25. That is,the main passage 21 a is arranged on the center line CT, and thedivision passages 21 b and 21 c are arranged on both outer sides of themain passage 21 a with respect to the longitudinal direction A.

In addition, the suction inlet 4 is divided by the partition walls 25into suction inlets 4 a, 4 b, and 4 c. The suction inlets 4 a, 4 b, and4 c are arranged at upstream ends of the main passage 21 a, the divisionpassage 21 b, and the division passage 21 c, respectively. Each of thesuction inlets 4 b and 4 c is arranged adjacent to the suction inlet 4a.

Each partition wall 25 includes an upstream vertical portion 25 a, afirst curved portion 25 b, a second curved portion 25 c, and adownstream vertical portion 25 d arranged in the order named from theupstream side to the downstream side with respect to the direction inwhich the air flows. The upstream vertical portion 25 a is arranged atan upstream end of the partition wall 25, and is arranged to besubstantially perpendicular to the longitudinal direction A. That is,each partition wall 25 includes the upstream vertical portion 25 a,which is substantially perpendicular to the longitudinal direction A, atthe upstream end thereof. The first curved portion 25 b is definedcontinuously with a downstream side of the upstream vertical portion 25a, and is arranged to curve so as to be convex away from the center lineCT (i.e., outward in the longitudinal direction A). That is, eachpartition wall 25 includes the first curved portion 25 b, which isdefined continuously with the downstream side of the upstream verticalportion 25 a and is arranged to curve so as to be convex away from thecenter line CT. The second curved portion 25 c is defined continuouslywith a downstream side of the first curved portion 25 b, and is arrangedto curve so as to be convex toward the center line CT (i.e., inward inthe longitudinal direction A). That is, each partition wall 25 includesthe second curved portion 25 c, which is defined continuously with thedownstream side of the first curved portion 25 b and is arranged tocurve so as to be convex toward the center line CT. The downstreamvertical portion 25 d is defined continuously with the second curvedportion 25 c at a downstream end, and is arranged to be substantiallyperpendicular to the longitudinal direction A. That is, each partitionwall 25 includes, at the downstream end thereof, the downstream verticalportion 25 d, which is defined continuously with the second curvedportion 25 c and is arranged to be substantially perpendicular to thelongitudinal direction A.

Thus, the upstream end of each partition wall 25 is arranged outward ofthe downstream end thereof with respect to the longitudinal direction A,so that a width W1 of the main passage 21 a at the suction inlet 4 ameasured in the longitudinal direction A is greater than a width W2 ofthe main passage 21 a at the outlet 22 measured in the longitudinaldirection A. A width W3 of the suction inlet 4 b measured in thelongitudinal direction A is smaller than a width W4 of the divisionpassage 21 b at the outlet 22 measured in the longitudinal direction A.A width W5 of the suction inlet 4 c measured in the longitudinaldirection A is smaller than a width W6 of the division passage 21 c atthe outlet 22 measured in the longitudinal direction A.

The width W3 of the suction inlet 4 b and the width W5 of the suctioninlet 4 c are arranged to be substantially equal to each other, and thewidth W1 of the suction inlet 4 a is arranged to be greater than thewidth W3 of the suction inlet 4 b and the width W5 of the suction inlet4 c. The width W4 of the division passage 21 b at the outlet 22 and thewidth W6 of the division passage 21 c at the outlet 22 are arranged tobe substantially equal to each other. In addition, since each of thedivision passages 21 b and 21 c becomes wider on the downstream side,each of the width W4 of the division passage 21 b at the outlet 22 andthe width W6 of the division passage 21 c at the outlet 22 approachesthe width W2 of the main passage 21 a at the outlet 22. In the presentpreferred embodiment, the width W2 of the main passage 21 a at theoutlet 22, the width W4 of the division passage 21 b at the outlet 22,and the width W6 of the division passage 21 c at the outlet 22 arearranged to be substantially equal to one another. Note that the widthW3 of the suction inlet 4 b and the width W5 of the suction inlet 4 cmay be different from each other.

Note that the number of partition walls 25 is not limited to two, butmay alternatively be an even number equal to or greater than four. Inthis case, the suction passage 21 is divided into one main passage andan even number of division passages, the even number being equal to orgreater than four.

If a cleaning start time previously stored in the storage portion of theelectric vacuum cleaner 1 having the above-described structure comes,the case 2 leaves the charger stand and automatically travels on thefloor F. At this time, the electric blower 7 is driven, and the rotarybrush is caused to rotate. The cleaning operation of the electric vacuumcleaner 1 is thus started. Air flows including dust on the floor F enterinto the main passage 21 a and the division passages 21 b and 21 cthrough the suction inlets 4 a, 4 b, and 4 c, respectively, as indicatedby arrows S (see FIG. 5).

At this time, the upstream vertical portion 25 a of each partition wall25 contributes to reducing turbulence in the vicinity of the upstreamend of the partition wall 25. Thus, the air flow smoothly enters intoeach of the main passage 21 a and the division passages 21 b and 21 c.After entering into each of the main passage 21 a and the divisionpassages 21 b and 21 c, the air flows along the first curved portion 25b and then the second curved portion 25 c. Thus, the air which hasflowed into each of the division passages 21 b and 21 c is smoothlyguided toward the center line CT. This contributes to reducingturbulence of the air in each of the division passages 21 b and 21 c,and causing the air to flow more smoothly therein.

In addition, because the widths W4 and W6 of the division passages 21 band 21 c, respectively, at the outlet 22 approach the width W2 of themain passage 21 a at the outlet 22, suction forces of equivalentmagnitude act in the main passage 21 a and the division passages 21 band 21 c. Thus, suction forces are substantially evenly distributed inthe longitudinal direction A of the suction inlet 4.

In addition, the width W1 of the suction inlet 4 a of the main passage21 a, where turbulence does not easily occur, is arranged to be greaterthan the widths W3 and W5 of the suction inlets 4 b and 4 c,respectively, and this leads to improved suction efficiency of thesuction nozzle 20.

In addition, the downstream vertical portion 25 d of each partition wall25 contributes to causing air which has reached a downstream portion ofeach of the main passage 21 a and the division passages 21 b and 21 c tobe smoothly guided downstream of the outlet 22.

After passing in the main passage 21 a and the division passages 21 band 21 c, the air flows enter into the dust collection portion 8 throughthe outlet 22. At this time, dust D in the air is blocked by the filter9, and is collected in the dust collection portion 8. After passingthrough the filter 9, the air flows in a portion of the air passage 6 onthe downstream side of the filter 9, and is then sent out of the case 2through the discharge outlet 5. The floor F is cleaned in theabove-described manner.

After traveling over the entire floor F while keeping the electricblower 7 in operation, the electric vacuum cleaner 1 returns to thecharger stand, and the electric blower 7 is stopped. The cleaningoperation of the electric vacuum cleaner 1 is thus completed.

FIGS. 6 and 7 are a perspective view and a side view, respectively,illustrating a result of a simulation of flows of air in the portion ofthe air passage 6 on the suction side. In these figures, almost noturbulence can be observed in any of the main passage 21 a and thedivision passages 21 b and 21 c, and air flows in a laminar state ineach of the main passage 21 a and the division passages 21 b and 21 c.In addition, a turbulent flow that is so large as to rescatter theaccumulated dust cannot be observed in the dust collection portion 8.

For a comparative example, a similar simulation was performed with thepartition walls 25 being omitted, and the result was that largeturbulent flows were observed in the dust collection portion 8 and bothend portions of the suction passage 21 with respect to the longitudinaldirection A.

FIG. 8 is a side view illustrating a result of a simulation of an airvelocity distribution in the portion of the air passage 6 on the suctionside. The result shows that, in the suction passage 21, air flows at asubstantially uniform velocity at about 25 m/s, and in the dustcollection portion 8, air flows at a substantially uniform velocity atabout 0.041 m/s. In contrast, in the aforementioned comparative example,the air velocity varied widely in both the suction nozzle 20 and thedust collection portion 8.

FIG. 9 is a side view illustrating a result of a simulation of an airpressure distribution in the portion of the air passage 6 on the suctionside. This figure shows that air pressure is substantially uniform inthe suction nozzle 20 and the dust collection portion 8 at about −230Pa. In contrast, in the aforementioned comparative example, the airpressure varied widely in the suction nozzle 20 and the dust collectionportion 8.

The above results show that the suction nozzle 20 according to thepresent preferred embodiment is able to reduce turbulence in both thesuction passage 21 and the dust collection portion 8.

In the present preferred embodiment, the plurality of partition walls25, which are arranged to divide the suction passage 21 into the mainpassage 21 a and the division passages 21 b and 21 c which are dividedfrom one another in the longitudinal direction A of the suction inlet 4,are provided in the suction nozzle 20. This prevents a narrowing of achannel on a side closer to an air inlet of the electric blower 7 fromcausing flows of air sucked in through both end portions of the suctioninlet 4 with respect to the longitudinal direction A to abruptly bendtoward the center line CT immediately after entering into the suctionpassage 21, and thus contributes to reducing turbulence of the air.

In addition, the width W1 of the main passage 21 a at the suction inlet4 measured in the longitudinal direction A is greater than the width W2of the main passage 21 a at the outlet 22 measured in the longitudinaldirection A. This causes each of the widths W4 and W6 of the divisionpassages 21 b and 21 c, respectively, at the outlet 22 to approach thewidth W2 of the main passage 21 a at the outlet 22, resulting in anincrease in the suction force that acts in each of the division passages21 b and 21 c. Thus, the suction forces are substantially evenlydistributed over the suction inlet 4 in the longitudinal direction A.This leads to improved suction efficiency of the suction nozzle 20.

In addition, each partition wall 25 includes the upstream verticalportion 25 a, which is substantially perpendicular to the longitudinaldirection A, at an upstream end of the suction passage 21. Thiscontributes to further reducing turbulence in the vicinity of theupstream end of the partition wall 25.

In addition, each partition wall 25 includes the first curved portion 25b, which is defined continuously with the downstream side of theupstream vertical portion 25 a and is arranged to curve so as to beconvex away from the center line CT. This contributes to causing airsucked in through the suction inlets 4 b and 4 c at both end portionswith respect to the longitudinal direction A to smoothly flow in thedivision passages 21 b and 21 c.

In addition, each partition wall 25 includes the second curved portion25 c, which is defined continuously with the downstream side of thefirst curved portion 25 b and is arranged to curve so as to be convextoward the center line CT. This contributes to causing the air sucked inthrough the suction inlets 4 b and 4 c at both end portions with respectto the longitudinal direction A to be smoothly guided to a downstreamportion of the suction passage 21.

In addition, each partition wall 25 includes, at the downstream endthereof, the downstream vertical portion 25 d, which is definedcontinuously with the second curved portion 25 c and is arranged to besubstantially perpendicular to the longitudinal direction A. Thiscontributes to causing the air flowing in each of the main passage 21 aand the division passages 21 b and 21 c to be smoothly guided to theoutlet 22.

In addition, the width W1 of the main passage 21 a at the suction inlet4 measured in the longitudinal direction A is arranged to be greaterthan each of the widths W3 and W5 of the division passages 21 b and 21c, respectively, at the suction inlet 4 measured in the longitudinaldirection A. Arranging air to be sucked in through three separatesuction inlets as described above contributes to reducing the likelihoodof an occurrence of turbulence in the suction nozzle 20, and increasingthe amount of air sucked in by the suction nozzle 20. Further, arrangingeach of the division passages 21 b and 21 c, which are relativelynarrow, on the outer side with respect to the longitudinal direction Aof the suction inlet 4 contributes to further improving suctionefficiency at end portions of the suction nozzle 20 with respect to thelongitudinal direction A, at which weak suction forces tend to beobserved most often in related art.

In addition, the electric vacuum cleaner 1 includes the suction nozzle20, the dust collection portion 8 arranged downstream of the suctionnozzle 20, and the electric blower 7 arranged downstream of the dustcollection portion 8. The electric vacuum cleaner 1 is thus able toeasily achieve improved suction efficiency and cleaning efficiency. Inaddition, because air flows in the laminar state in each of the mainpassage 21 a and the division passages 21 b and 21 c, the dust D can besmoothly sucked in through even the suction inlets 4 b and 4 c at bothend portions with respect to the longitudinal direction A without anincrease in the rotation rate of the electric blower 7. This contributesto reducing the turbulence in the dust collection portion 8, andpreventing the dust D accumulated in the dust collection portion 8 frombeing rescattered.

In addition, the suction passage 21 is arranged to extend upward fromthe suction inlet 4, and is connected to the upper portion of the dustcollection portion 8, and the upper side of a portion of the dustcollection portion 8 is covered with the suction nozzle 20. Thiscontributes to reducing the size of the electric vacuum cleaner 1.

Note that, in the present preferred embodiment, the first curved portion25 b may alternatively be arranged to extend from a downstream end ofthe upstream vertical portion 25 a to the outlet 22 with the secondcurved portion 25 c and the downstream vertical portion 25 d beingomitted.

Next, a second preferred embodiment of the disclosure will now bedescribed below. FIG. 10 is a perspective view of a portion of an airpassage on the suction side including a suction nozzle of an electricvacuum cleaner according to the second preferred embodiment. FIG. 11 isa sectional front view of the suction nozzle of the electric vacuumcleaner according to the second preferred embodiment. For the sake ofconvenience in description, members or portions that have theirequivalents in the above-described first preferred embodimentillustrated in FIGS. 1 to 9 are denoted by the same reference numeralsas those of their equivalents in the first preferred embodiment. Thesecond preferred embodiment is different from the first preferredembodiment in the shape of partition walls 25. The second preferredembodiment is otherwise similar to the first preferred embodiment.

In a suction passage 21, a plurality of plate-shaped partition walls 25are arranged side by side in the longitudinal direction A. Eachpartition wall 25 is defined by a plate perpendicular to a lower wall 28b, and is arranged to extend in a straight line from a side on which asuction inlet 4 is defined to a side on which an outlet 22 is defined.That is, the partition wall 25 is in the shape of a plate, and isarranged to extend in a straight line from the side on which the suctioninlet 4 is defined to the side on which the outlet 22 is defined. In afront view, two of the partition walls 25 are arranged to incline towardeach other as they extend from the suction inlet 4 toward the outlet 22.

The present preferred embodiment is able to achieve beneficial effectssimilar to those of the first preferred embodiment. In addition, eachpartition wall 25 is in the shape of a plate, and is arranged to extendin a straight line from the side on which the suction inlet 4 is definedto the side on which the outlet 22 is defined. This contributes toeasily preventing a separation of an air flow passing in each of a mainpassage 21 a and division passages 21 b and 21 c from any partition wall25, and further reducing the likelihood of an occurrence of turbulence.

Next, a third preferred embodiment of the disclosure will now bedescribed below. FIG. 12 is a perspective view of a portion of an airpassage on the suction side including a suction nozzle of an electricvacuum cleaner according to the third preferred embodiment. FIG. 13 is asectional front view of the suction nozzle of the electric vacuumcleaner according to the third preferred embodiment. For the sake ofconvenience in description, members or portions that have theirequivalents in the above-described first preferred embodimentillustrated in FIGS. 1 to 9 are denoted by the same reference numeralsas those of their equivalents in the first preferred embodiment. Thethird preferred embodiment is different from the first preferredembodiment in the shape of partition walls 25. The third preferredembodiment is otherwise similar to the first preferred embodiment.

Each partition wall 25 includes an upstream vertical portion 25 a, astraight portion 25 e, and a downstream vertical portion 25 d arrangedin the order named from the upstream side to the downstream side withrespect to the direction in which air flows. The third preferredembodiment is different from the second preferred embodiment in thateach partition wall 25 includes the downstream vertical portion 25 d,which is arranged to be substantially perpendicular to the longitudinaldirection A, at a downstream end thereof. This causes air which hasreached a downstream portion of each of a main passage 21 a and divisionpassages 21 b and 21 c to be smoothly guided downstream of an outlet 22.The straight portion 25 e is defined continuously with each of adownstream end of the upstream vertical portion 25 a and an upstream endof the downstream vertical portion 25 d, and is arranged to extend in astraight line.

The present preferred embodiment is also able to achieve beneficialeffects similar to those of the first preferred embodiment. Note thatthe upstream vertical portion 25 a or the downstream vertical portion 25d may alternatively be omitted in the present preferred embodiment.

Next, a fourth preferred embodiment of the disclosure will now bedescribed below. FIG. 14 is a perspective view of an electric vacuumcleaner according to the fourth preferred embodiment. FIGS. 15 and 16are a sectional front view and a side sectional view, respectively, of asuction nozzle of the electric vacuum cleaner according to the fourthpreferred embodiment. For the sake of convenience in description,members or portions that have their equivalents in the above-describedfirst preferred embodiment illustrated in FIGS. 1 to 9 are denoted bythe same reference numerals as those of their equivalents in the firstpreferred embodiment. The fourth preferred embodiment is different fromthe first preferred embodiment in that a so-called canister-typeelectric vacuum cleaner 30 is used instead of the robot-type electricvacuum cleaner 1. The fourth preferred embodiment is otherwise similarto the first preferred embodiment.

The electric vacuum cleaner 30 includes an air inlet 31 and a dischargeoutlet 5 in a front surface and a rear surface, respectively, of a case2 thereof. An air passage 6, which is arranged to connect the air inlet31 and the discharge outlet 5, is defined in the case 2. In the airpassage 6, a dust collection portion 8, a filter 9, and an electricblower 7 are arranged in the order named from the upstream side to thedownstream side. Left and right wheels 39 are attached to side surfacesof the case 2. In addition, the electric vacuum cleaner 30 is providedwith a power supply cord (not shown) which is capable of being connectedto a commercial power supply (not shown).

A hose 32 is connected to the air inlet 31 of the case 2, and aconnection pipe 34 is connected to an upstream end of the hose 32. Ahandle portion 35 and an operation portion 16 are arranged in theconnection pipe 34. The operation portion 16 is operated to issue aninstruction to turn on or off the electric vacuum cleaner 30, aninstruction to change the rotation rate of the electric blower 7, or thelike. An extension pipe 33 is attached to an upstream end of theconnection pipe 34. A suction nozzle 20 is attached to an upstream endof the extension pipe 33 such that the suction nozzle 20 is detachablefrom the extension pipe 33.

The suction nozzle 20 includes a joint pipe 27 connected to theextension pipe 33 at the rear of a housing 26 thereof, and an outlet 22is open at a downstream end of the joint pipe 27. A width W7 of theoutlet 22 measured in the longitudinal direction A is arranged to besmaller than a width W8 of a suction inlet 4 measured in thelongitudinal direction A. A width of an opening portion 29 at anupstream end of the joint pipe 27 measured in the longitudinal directionA is arranged to be substantially equal to the width W7 of the outlet22. In addition, downstream ends of partition walls 25 are arrangedwithin the range of the width W7 of the outlet 22 measured in thelongitudinal direction A.

If a user of the electric vacuum cleaner 30 having the above-describedstructure inserts a plug of the power supply cord into a socket (notshown), and operates the operation portion 16, the electric blower 7 isdriven. As a result, air including dust D flows into each of a mainpassage 21 a and division passages 21 b and 21 c through the suctioninlet 4 of the suction nozzle 20. At this time, because the downstreamends of the partition walls 25 are arranged within the range of thewidth W7 of the outlet 22 measured in the longitudinal direction A, airflowing in each of the main passage 21 a and the division passages 21 band 21 c is smoothly guided to the outlet 22.

After flowing through each of the main passage 21 a and the divisionpassages 21 b and 21 c, the air flows through the extension pipe 33, theconnection pipe 34, and the hose 32 in the order named, and then flowsinto the case 2 through the air inlet 31. The dust D in the air whichhas flowed into the case 2 is collected in the dust collection portion8. A floor F is thus cleaned.

The present preferred embodiment is also able to achieve beneficialeffects similar to those of the first preferred embodiment. In addition,the canister-type electric vacuum cleaner 30 is also able to achieveimproved suction efficiency and cleaning efficiency.

Next, a fifth preferred embodiment of the disclosure will now bedescribed below. FIG. 17 is a perspective view of an electric vacuumcleaner according to the fifth preferred embodiment. For the sake ofconvenience in description, members or portions that have theirequivalents in the above-described first preferred embodimentillustrated in FIGS. 1 to 9 are denoted by the same reference numeralsas those of their equivalents in the first preferred embodiment. Thefifth preferred embodiment is different from the first preferredembodiment in that a so-called stick-type electric vacuum cleaner 40 isused instead of the robot-type electric vacuum cleaner 1. The fifthpreferred embodiment is otherwise similar to the first preferredembodiment.

The electric vacuum cleaner 40 includes a case 2 including an air inlet41 and a discharge outlet 5 in a lower surface and an upper surface,respectively, thereof. An air passage 6, which is arranged to connectthe air inlet 41 and the discharge outlet 5, is defined in the case 2.In the air passage 6, a dust collection portion 8, a filter 9, and anelectric blower 7 are arranged in the order named from the upstream sideto the downstream side. In addition, the electric vacuum cleaner 40 isprovided with a power supply cord (not shown) similar to that of thefourth preferred embodiment.

A handle portion 35 and an operation portion 16 are arranged at an upperportion of the case 2. A suction pipe 47 in the shape of a stick isconnected to the air inlet 41 of the case 2. A suction nozzle 20 isattached to an upstream end of the suction pipe 47 such that the suctionnozzle 20 is detachable from the suction pipe 47. The suction nozzle 20according to the present preferred embodiment is similar in structure tothe suction nozzle 20 according to the fourth preferred embodiment.

The present preferred embodiment is also able to achieve beneficialeffects similar to those of the first preferred embodiment. In addition,the stick-type electric vacuum cleaner 40 is also able to achieveimproved suction efficiency and cleaning efficiency.

Next, a sixth preferred embodiment of the disclosure will now bedescribed below. FIG. 18 is a perspective view of an electric vacuumcleaner according to the sixth preferred embodiment. For the sake ofconvenience in description, members or portions that have theirequivalents in the above-described first preferred embodimentillustrated in FIGS. 1 to 9 are denoted by the same reference numeralsas those of their equivalents in the first preferred embodiment. Thesixth preferred embodiment is different from the first preferredembodiment in that a so-called handy-type electric vacuum cleaner 50 isused instead of the robot-type electric vacuum cleaner 1. The sixthpreferred embodiment is otherwise similar to the first preferredembodiment.

The electric vacuum cleaner 50 is similar in structure to the electricvacuum cleaner 40 according to the fifth preferred embodiment with thesuction pipe 47 being omitted. A user can clean a floor F, a desktop(i.e., a surface to be cleaned), or the like with the electric vacuumcleaner 50 while holding a handle portion 35.

The present preferred embodiment is also able to achieve beneficialeffects similar to those of the first preferred embodiment. In addition,the handy-type electric vacuum cleaner 50 is also able to achieveimproved suction efficiency and cleaning efficiency.

Note that, instead of the partition walls 25 according to the firstpreferred embodiment, partition walls similar to the partition walls 25according to one of the second and third preferred embodiments mayalternatively be arranged in the suction nozzle 20 according to each ofthe fourth to sixth preferred embodiments.

Also note that a rotary brush may be arranged in the suction inlet 4 ofthe suction nozzle 20 according to each of the fourth to sixth preferredembodiments.

Preferred embodiments of the disclosure are applicable to suctionnozzles and electric vacuum cleaners including suction nozzles.

Features of the above-described preferred embodiments and themodifications thereof may be combined appropriately as long as noconflict arises.

While preferred embodiments of the disclosure have been described above,it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the disclosure. The scope of the disclosure, therefore, isto be determined solely by the following claims.

What is claimed is:
 1. A suction nozzle to be provided in an electricvacuum cleaner including an electric blower, the suction nozzlecomprising: a suction inlet arranged to extend in a longitudinaldirection that is predetermined, and arranged opposite to a surface tobe cleaned; an outlet to be connected to the electric blower; a suctionpassage arranged to extend along a center line joining a middle of thesuction inlet in the longitudinal direction and a middle of the outletin the longitudinal direction to connect the suction inlet and theoutlet; and a plurality of partition walls each of which is arranged inthe suction passage to extend from a side on which the suction inlet isdefined to a side on which the outlet is defined; wherein the suctionpassage includes: a main passage having the center line of the suctionpassage passing therethrough; and a plurality of division passagesarranged on both outer sides of the main passage with respect to thelongitudinal direction with one of the plurality of partition wallsbeing arranged between the main passage and an adjacent one of theplurality of division passages on either side of the main passage, themain passage and the plurality of division passages being divided fromone another in the longitudinal direction of the suction inlet by theplurality of partition walls; and a width of the main passage at thesuction inlet measured in the longitudinal direction is arranged to begreater than a width of the main passage at the outlet measured in thelongitudinal direction.
 2. The suction nozzle according to claim 1,wherein each partition wall includes, at an upstream end thereof, anupstream vertical portion arranged to be substantially perpendicular tothe longitudinal direction.
 3. The suction nozzle according to claim 2,wherein each partition wall further includes a first curved portiondefined continuously with a downstream side of the upstream verticalportion, and arranged to curve so as to be convex away from the centerline.
 4. The suction nozzle according to claim 3, wherein each partitionwall further includes a second curved portion defined continuously witha downstream side of the first curved portion, and arranged to curve soas to be convex toward the center line.
 5. The suction nozzle accordingto claim 4, wherein each partition wall further includes, at adownstream end thereof, a downstream vertical portion definedcontinuously with the second curved portion, and arranged to besubstantially perpendicular to the longitudinal direction.
 6. Thesuction nozzle according to claim 1, wherein each partition wallincludes, at a downstream end thereof, a downstream vertical portionarranged to be substantially perpendicular to the longitudinaldirection.
 7. The suction nozzle according to claim 1, wherein eachpartition wall is in a shape of a plate, and is arranged to extend in astraight line from the side on which the suction inlet is defined to theside on which the outlet is defined.
 8. The suction nozzle according toclaim 1, wherein a width of the outlet measured in the longitudinaldirection is arranged to be smaller than a width of the suction inletmeasured in the longitudinal direction; and downstream ends of thepartition walls are arranged within a range of the width of the outletmeasured in the longitudinal direction.
 9. The suction nozzle accordingto claim 1, wherein the width of the main passage at the suction inletmeasured in the longitudinal direction is arranged to be greater than awidth of each division passage at the suction inlet measured in thelongitudinal direction.
 10. An electric vacuum cleaner comprising: thesuction nozzle of claim 1; a dust collection portion arranged downstreamof the suction nozzle; and the electric blower arranged downstream ofthe dust collection portion.
 11. The electric vacuum cleaner accordingto claim 10, wherein the suction passage is arranged to extend upwardfrom the suction inlet, and is connected to an upper portion of the dustcollection portion, and an upper side of a portion of the dustcollection portion is covered with the suction nozzle.